1. We are just beginning to design PWBs with BGAs.  Some of our PWB 
suppliers have said that they are seeing the absence of thermals around vias 
on the power planes and thought this was they way the industry was headed.

Is this true?
What is the down side for PWB fab and assembly?  Reliability?

2. Is HASL still the finish of choice for this technology or are 
alternatives to HASL preferred?

3. Traditionally, we require 100% plugging of vias that are not test points 
before HASL and have 2 coats LPI on the PWBs.  This has met the needs for 
corrosion protection, vacuum for test and assembly (as long as the height is 
controlled).   Is this reasonable for BGA designs?

4. From those with more experience designing for BGAs, are there lessons 
that you've learned and could share?  From PWB suppliers?  Assemblers?

Marti Tully Sr. Supply Quality Engineer

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************